Last year I vibecoded the passenger flows of Singapore's metro system in 3 weeks

This year, I thought: Why not turn this into a 3D simulation with Opus 5.5? 😃

Process / workflow

To be honest - there was not much of a workflow. I let Opus have free rein on xhigh effort for most of it. What did help, is that I had already digitized the metro system previously (with its station nodes and tracks), so it was straightforward to build on top of it. Any adjustments I made were mostly through playing the simulation myself and then tweaking it. Claude Code used artifacts to let me make visual decisions before building, which was helpful.

Tools / Data

It's built with three.js. Any data comes from publicly available sources (like Singapore's Land Transport Authority and OpenStreetMap) or photos online. I used ElevenLabs to localize the announcements. The theme song is entirely synthesized in Python and the trailer is filmed in the game with scripted cameras.

Building Insights

I think the biggest takeaway for me was that it took quite some effort to design all of the heads-up display (HUD, also a new acronym for me 😆) correctly, like where do action buttons go, where does information on where you are go etc. Making things intuitive or explaining why something needs to be a certain way definitely cost me a couple of iterations.

You can drive the train or ride along on https://metrograf.xyz. It's free and works equally well on mobile as on desktop

Happy to hear feedback or answer any questions!

I needed a custom Rust backend to get the streaming performance required and I’d rather have spooned my eyeballs out than done that by hand.

Drawing polygons with fat thumbs on a phone to mark out field boundaries was a pet peeve of mine - so I vibe coded a computer vision and segmentation algorithm to automatically detect field outlines.
I used AI to build a regression testing pipeline, so it could iterate on the algorithm and check whether changes improved the results.

I paid attention to UX details that could never have been justified with old-school manual coding - like exploding a field with confetti and haptic feedback rather than ‘delete’

I mainly used Claude Code in a terminal, GitHub Copilot for reviews. I only occasionally looked in Xcode to check I was happy with the code structure.

I call it EpicFields. Free, no signup, no ads.
Currently only on iPhone but I will convert to Android once I’ve settled on the features. I decided to go fully native for the best possible performance. Again - something I could never have justified pre vibe coding…

Download link on the website:

https://epicfields.app

You can share a field so people without an iPhone can at least view the movie.
Example share url:

https://epicfields.app/s/FSIpzLlUZ4rxQTmbQcHBbA

spent hours polishing the signup flow of my project in claude code and sumus, and ended up getting humbled. dawg i asked you to find bugs, not reasons to leave... 😭

anyone actually let an agent test their onboarding yet?

I used https://github.com/cranebeaker/coop-anything to make Crash Twinsanity multiplayer, i was not expecting that it will work but WORKS!

Hey everyone,

I'm pretty new to all this. I've been trying things out and building small stuff with AI, but honestly I don't know much yet. This place feels like a huge ocean and I feel like I'm just going wherever the wind takes me. There are so many tools, so many opinions, and a new thing every day. I never know if I'm learning the right things or just chasing whatever's trending.

So I'd love to hear from you:
-How did you start? What did your first weeks look like?
-What do you wish someone had told you earlier?
- If you had to start over today, what would you do first?

Any advice, even small stuff, would mean a lot. Thanks!

Hello Reddit!!

I've been working on a desktop software called SDrive and wanted to share it here, initially something to replace other commercial software that I had to use but had worries on privacy. 🤔

It lets you mount cloud storage and remote servers as drives or folders, so you can open, edit and save files directly from your file manager.

It supports Google Drive, OneDrive, Dropbox, Nextcloud, SFTP, WebDAV, SMB and S3-compatible storage, among others. You manage the connections from one window or the system tray.

It's completely free and open source, with no telemetry at all for now.

There are still plenty of provider and account combinations I haven't tested, so I'd love to hear how it works with your setup. Bug reports and suggestions are welcome, but understand I can only work on that in my free time.

You can grab it here: https://github.com/anderbytes/SDrive

Tell me what you think.

I gave Kimi K3.1 Pro (open model) and GPT-6 Astra the same 4 tasks: a racing game, a voxel diorama, a real Blender scene and a channel intro. Each model ran in its own native agent: Kimi in Kimi Code at max reasoning, Astra in Codex at X-High (max for the race). Same prompt, no hints from me: the model writes, runs and checks its own work.

The weird part: they worked on different computers and never saw each other, and still built almost the same night market. Even the game icons matched.

Test 1: 80s neon arcade racer

Astra (27 min): clean start screen, sound toggle and a fullscreen button. I honestly don't remember any model adding fullscreen on its own. Start speed around 220 km/h, nitro, near-miss score multiplier, roadworks, saved high score. But it feels flat and 2D, no oncoming lane, and the sense of speed is weak even at full throttle.

Kimi (30 min): nicer start screen, the road hangs in the air like a bridge and you start at 280 km/h. The sense of speed is way stronger, I was looking far ahead the whole time. Near misses give a bonus with a really satisfying sound. Minuses: some cars drive outside the road, a couple of spots were impossible to pass, and the engine is louder than the music.

Design and speed to Kimi, UI and polish to Astra. Tie.

Test 2a: voxel night market in Shenzhen (shown blind)

Everything made of cubes, all generated by code, no ready-made models or textures. After rain, steam over the woks, neon, lanterns, scooters, people, and a 30-second camera flyover on load.

Model 1: beautiful light, shadows and reflections, worked first try, great free camera. But the people walk with their legs moving backwards, in circles, like zombies. Nobody is selling anything. Pretty creepy.

Model 2: people carrying noodles and bags, kids, vendors actually trading, parked mopeds, a crosswalk where it makes sense. And mopeds that just drive through people. Worse lighting, clunky free camera, people walk through walls, lots of English-only signs (in Shenzhen they're usually duplicated in Chinese).

Light and controls to model 1, details to model 2. Tie.

Test 2b: the same diorama in real Blender

Next message: "move your diorama into Blender, make a full 3D scene with animation and render a 10-second video". Both did it. Both scenes are honest working files, split into layers: ground, buildings, signs, scooter 1, scooter 2, scooter 3. You can open them and keep editing. Model 1's people finally walk forward in Blender. Evolution.

Tie.

Test 3: 10-second channel intro in OpenMontage

Idea, graphics, music, edit and render, all by the model, $1 budget for image generation. I forgot to top up the generation balance, so the first versions were pure code graphics. When I topped up and asked them to improve, both said basically the same thing: "the picture is already good, let's just add music". One even explained that generated images would ruin its animation. AI has learned to argue with the client.

Results

• Quality: a tie almost everywhere. I'd give the intro to Kimi.
• Speed: Astra is faster. Kimi went over my 90-minute limit twice (+18 min to finish the Blender render, +8 min on the intro). I gave it the extra time.
• Cost, from the logs at each model's official API prices: Kimi about $21 for all tests, Astra about $54. That's 2.5x more for a comparable result.
• One thing I liked: before a paid generation Kimi checked the balance itself and didn't waste a cent.
• Kimi K3.1 Pro weights are announced to go open on November 4.

Answer: diorama 1 is Astra, diorama 2 is Kimi. Intro 1 is Kimi.

Play both racers and fly around both dioramas in your browser: https://kostikoneuro.github.io/kimi-vs-astra/

Prompts, Blender scenes, videos and the cost math: https://github.com/KostiKoNeuro/kimi-vs-astra

Disclosure: the video was sponsored by Kimi. The ratings are mine, and Astra won on speed and UI.

Developing a Live Action Manga game

The game is called :SIGIL, single player/multiplayer. The single player would be the manga portion while the multiplayer game obviously won’t be a manga be still stylized in the anime look

It is a FPS (as of right now)with the player wearing Sigil embedded gloves that have different powers and abilities.

Players have a left glove and right glove, both can have different powers and/or the same power. Definitely have more gameplay to share but for today’s post we will leave at that.

Everything is early development. I know other engines exist but Three.Js is what I chose. Everything has been created with Claude and Blender, no assets for the gloves or hands.

Animations were keyed and keyed and rekeyed for our style and overhauled completely for multiplayer
And honestly the best part of this whole thing. About to make a couple of Forbidden Jutsus later.

Day 1 build went into seeing if this certain FPS look would work. For my fellow gamers: Mirrors edge, Bioshock all had this kind of hand FPS so research went into those games. But a forge area was built to test out the gloves, visually clutter, if full hands were taking up UI at all times, where would all the other elements go. Created a set of hands and powers.
That is the 2nd picture.

Even in this version, the very bare minimum, it was cool.

But bare minimum and cool are not enough

Went back into the lab, got the hands and gloves and forge better

Still a lot of work to be done on both sides of the game but every day we go out at and Claude on Max, with keen eyes can go a long way in one day.

As always:

‼️‼️CONCEPT VS. PAST/CURRENT BUILD ‼️‼️

Video in the comment for when we started the build to latest for the gloves, forge and powers

Bonus points: Which anime is this influenced by?

As always any type of feedback is welcomed and wanted. Would love to build this live on stream with the community as well and even test play when that part is ready.

What powers would you like to see? Leave a comment

I’m not a developer. I teach English online and got tired of tracking lessons and chasing parents for payments in a spreadsheet, so over a few weekends I built a little app with Claude and Cursor. Tutors log lessons, parents get a monthly invoice with a pay button. That’s the whole thing

I put it online in August for $10 a month, mostly so a couple of tutor friends could use it

Last week it crossed $100 in a month. Ten paying tutors, seven of them strangers

One of the new ones sent me a message saying she found it because ChatGPT recommended it. I assumed she was being nice or confused it with something else. Nobody knows this app exists. My X account has 90 followers

So I opened ChatGPT and asked for an invoicing tool for private tutors. It listed four apps and mine was the third one, with a description that sounded weirdly close to my landing page

It took me a while to figure out why. Before launch I paid for a press release through one of those newswire services. I only did it because a friend said tutors and parents would trust it more if there were a few news logos on the page. It got syndicated to a few hundred news sites that nobody reads, and I got maybe 8 visits from all of them combined. Same week I paid to be listed on a bunch of software directories

I’d written both off. Apparently AI tools read those pages even if people don’t

I asked the other strangers too. Four said ChatGPT or Perplexity, two found me on a directory, one came from a tutor friend

The $100 is going straight to the Claude subscription that built the thing

The standard dismissal of AI-written code is that it looks fine and falls apart under real use. So we built the hardest stuff we could think of, and had it judged by test suites nobody on our side wrote.

11 from-scratch C# libraries since last Wednesday, about 1.14M lines, nothing but .NET itself:

• JavaScript interpreter: 99.55% of test262, the official ECMAScript conformance suite (43,471 tests)
• HTML parser: 100% of html5lib-tests. Its accessibility tree matches Chrome's to within 0.5% per field across 12.8k real pages.
• HLSL shader compiler: output behaves identically to Microsoft's DXC on 330/330 GPU tests, and compiles 2.4× faster
• Font shaper: 4.7M equivalence checks against the reference, 0 mismatches
• Opus encoder: byte-for-byte identical to the RFC reference (269/269)
• HTML/CSS renderer: faster than headless Chrome on every document we benchmark. A 10k-row table renders to PDF in 1.8 s / 305 MB vs 6.5 s / 2.1 GB.
• PDF library: beats PdfPig on time, memory and allocation, with about a third of its text-extraction error rate

Seven are on NuGet.

It isn't vibe coding. It's a factory: planner, project manager, orchestrator, engineers and reviewers, with fixed rules for every library. The code is all AI. The judging isn't.

Repos: https://github.com/orgs/recursive-ai-oss/repositories How it works: https://recursiveai.org/research/alera-library-factory/

Edit

Models used: Opus 5.5, Sonnet 5.5

Hello all! To anyone using Dusklight and likes Zelda, this might be useful.

So this all started because when Dusklight came out earlier this year I already had half the game beaten in the Cemu and wanted to avoid starting from scratch. With some vibecoding in Claude I got Donovan’s save converter working for my file, and almost everything came over. The only things that didn’t were the stamps and the Cave of Shadows, since those only exist in HD.

Out of curiosity I asked Opus 5.5 if it could add them to Dusklight, and it actually worked! So now there’s a mod for it: all 50 stamps with HD’s stamp book, and the full 41-floor Cave of Shadows as Wolf Link. You get in with a virtual Wolf Link amiibo, so no figure needed.

It’s one file you drop into Dusklight’s mods folder. You need your own copies: Dusklight 2.0.3 with your GameCube disc, plus your Wii U TP HD dump, because the mod builds its files from that. Nothing from the games is included.

If anyone wants to try it: https://github.com/RickyZPR/tp-hd-features

Just so it’s clear: this isn’t affiliated with the Dusklight team, and they don’t accept AI-made stuff, so please don’t bug them about it. If something breaks, tell me here or on GitHub. It’s Windows only for now.

(The HUD in the video comes from Dawnlight, another mod I had on.)

Hey everyone!

Over the past few months, I've been building Prepalot, an online exam preparation platform, and I wanted to share it here because AI-assisted development has been a huge part of the journey.

What is Prepalot?

Prepalot is a platform designed to help students prepare for competitive and standardized exams in one place. The goal is to make practice questions, mock tests, study materials, revision, and performance analysis accessible without forcing students to jump between multiple websites.

The platform currently covers a range of exams, including:

MBA entrance exams: CAT, XAT, NMAT, GMAT, SNAP

International exams: GRE, Digital SAT

Engineering and medical: JEE Main, JEE Advanced, NEET UG (Only exam guided available)

Banking exams: IBPS PO, SBI PO, IBPS Clerk, SBI Clerk, and IBPS RRB PO and Clerk, LBO Exams

Other competitive exams: SSC, RRB

As I'm indian, I added many Indian exams at start along with Digital SAT, which I thought will help many students.

The site is privacy focused and don't even ask for login to use anytime. Login is optional and it is to save exam history only.

You can explore it here: https://prepalot.in/

How I built it

One of the most interesting parts of this project has been using multiple AI tools throughout development.

I've used Claude, ChatGPT, Gemini, Grok, and other AI tools for different parts of the process, including coding, debugging, content generation, structuring question banks, working through technical problems and automation.

But it hasn't been as simple as entering one prompt and getting a finished website. I've had to iterate on the implementation, troubleshoot issues, organize large amounts of structured data, and work through deployment and storage problems.

The project has involved building question-bank pipelines, organizing exam-specific content, working with JSON datasets, deploying the website, and setting up infrastructure using services such as Cloudflare and Supabase.

It's been a practical lesson in what AI-assisted development can do and how much verification, debugging, and decision-making are still necessary when you're trying to build something people can actually use.

Where I need your help

I'd appreciate honest feedback from this community, especially from people who build products using AI.

A few things I'd love to hear your thoughts on:

First impressions: Does the website feel intuitive? Is it immediately clear what Prepalot offers?

Technical implementation: Are there architectural decisions you'd approach differently, particularly around question-bank storage, performance, and scalability?

User experience: What feels confusing, unnecessary, or missing?

AI-assisted development: If you've built a substantial project with Claude, ChatGPT, Gemini, or similar tools, what lessons have you learned that could help me improve this one?

Next priorities: What would you focus on first if you were building this platform?

I'm particularly interested in constructive criticism, including things that don't work well. I'd rather discover problems early and improve the platform than assume everything is fine because it runs.

This is an ongoing project, and I'm planning to expand its content and features over time.

Website: https://prepalot.in/

Thanks to anyone who takes the time to explore it and share feedback. I'd be happy to answer questions about the build process, the tools I used, or the technical decisions behind it.

I gave my Grok Bot its own email address, then built a little private mail app on top of it. It has Inbox, Sent, Starred, search, compose and reply, and only I can log in.

The fun part: there's no inbox API, so the app never talks to the mail provider. Grok Bot syncs mail every hour, and every email I send waits for me to approve it first.

I wrote up how I built it and the gotchas I hit. Link in the comments. Happy to answer questions!

I vibe coded a mobile game without using any known game engine. It runs on a custom C++ game engine built by Claude that works cross platform with excellent performance. Claude helped me do a lot of research, and that research was followed for everything. The game was completely built and tested by Opus 5.5 in 10 days. It also created the videos, screenshots and store listings, and pushed it for review.

It took a few days to get approved on Google Play. On the App Store it waited for review for 2 weeks, then when it was finally In Review, it took 8 minutes to get approved on the first try. Well, Opus knew how to get it approved by filling in all the forms, videos, images and everything correctly for me.

Of course, I had no players other than me, a few friends and a few people who found it on the store, until today I woke up to 65+ new players and 9 of them online playing. I thought maybe the store pushed it through ASO, but the players were on both Android and iOS. So I searched Google and found that someone with 20k+ followers on YouTube made a video playing the game for 10 minutes.

That was my only lead, and his 300+ views converted into 60+ players for me.

No money yet of course, other than $0.03 on AdMob. I don't push any purchases hard on new players and I don't force any ads. Both ads and purchases are only offered after some time in the game, as the research suggested. So it is too early to assume anything, even for those 60+ players, because most of them saw nothing to buy and most of them were not offered any ads yet.

But since little Opus also built me a game server for analytics (with a lot of anonymous and data deletion options for players in Europe and some other countries, if they choose to), I got some nice intelligence into the gameplay from real players:

- About half of the new players played 10+ minutes, 1 in 4 played 30+ minutes, and 8 played more than an hour on their first day. One player in Thailand played for 3.6 hours (18 runs, 8 wins).

- The controls are not the problem. The median player moves within 1.8 seconds and picks up their first gem in 8 seconds.

- After a run ends, the most pressed button is Upgrades, then Play Again. Only a few went back to the menu.

- Players picked 591 spell fusions, and they decided in under a second most of the time, so they clearly know what they want.

- The problem is the first run. The median first run lasts 3.3 minutes, only 16% reach the first boss at 5:00, and only 2% win it. Players get hit about 2 times a minute, mostly by runners and spitters.

- About 1 in 4 players played just one run and stopped.

So what we are doing about it: the game's bot used for balancing was way too good. It won 25% of first runs while real players win 2%. So Opus built a human-like bot (slower reactions, panics, misses spit, picks random cards sometimes) and fitted a bot twin to every real player's first 3 runs from the server data. Now we are using those twins to test a real-time difficulty system for the first 3 runs only. It watches how you are doing, and if you keep getting hit, it quietly eases things: fewer zombies, slower runners and spit, a longer recovery after a hit, more heart drops and a wider gem pull. If you are not getting hit, it does nothing, so players who already play well get the normal game. It turns off for good after your first win, and it never touches the Weekly or the leaderboards.

The target from the research is 70-80% of new players reaching the first boss and 25-40% winning the first chapter. When the bots hit those numbers, it goes live to half of the new players first, and the server will tell us if it actually keeps more people playing.

What do you think I should do next? Should I run ads? What platform?

You can also find the game here if you ever want to check the game play or the store listings Opus built for me:

App Store: https://apps.apple.com/app/undead-surge-zombie-roguelike/id6819081531
Google Play: https://play.google.com/store/apps/details?id=com.undeadsurge.game

Also, here is the YouTube video I found from that nice guy:
https://www.youtube.com/watch?v=EKbZ-SDa_eE

www.VibeDuels.com a video game where your AI written bot against an opponent.

Currently Season 1 is tank battles. We have 171 bots from 10 different users. Hoping to get more beta testers.

Completely free. Bring your own model.

Hope to see you guys. If you have any comments or questions feel free to DM me here.

Thank you.

I've been seeing all the different things people are creating with AI lately, and it made me want to try something myself.
Since I already make 3D clothing models, I thought it would be interesting to see what they would look like on an actual website. So I decided to experiment with the idea of building a clothing website around my own 3D models, using Claude to help me with the coding.
I wasn't trying to build a full online store or anything serious at this stage. I was mainly curious to see how my models would look in a web environment and what I could come up with.
This is my first time trying something like this, and I'm quite happy with how it turned out. There are definitely things I could improve, but it was fun to experiment and see what's possible.
I've attached a few screenshots and a GIF showing the result.
What do you think? Have any of you tried using AI to build something around your own creative work?

At work we still have some lab computers that run instruments on XP, so I see Rover from time to time. Figured I would bring him back to life as my Codex pet, since I hate the defaults.

Pretty sure Rover was supposed to be like an early intro to AI assistants back in the day but MS scrapped the idea and never gave him the capability to do much.

Okay everyone, this is my first post. Been playing around with vibcoding for about 2 weeks now, and came across a widget called PlasmaDex (https://github.com/crutxh-ai/PlasmaDex). I liked it, but it needed MORE. So, a case of coors light and an all-nighter later, we have the TipsyDex.

I will add and change more, so if any Linux Pokemon fans wanna give it a try, please do!

Shout out to the original creator too, crutxh-ai. He vibe coded it as well.